Ganoderma lucidum fermentation liquor water extract for preventing and treating plant diseases and application thereof

Abstract

The present application belongs to the field of agricultural plant protection, and particularly relates to a ganoderma lucidum fermentation liquor water extract for preventing and treating plant diseases and application thereof. The ganoderma lucidum fermentation liquor water extract is prepared by segmental liquid fermentation, slag removal, 90-100 DEG C water extraction and purification of ganoderma lucidum. The present application uses the ganoderma lucidum fermentation liquor water extract as the only effective active ingredient, and is supplemented with an agriculturally acceptable adjuvant and / or filler to prepare a biological control agent. Experiments show that the biological control agent provided by the present application has a field control efficiency of more than 80% on wheat stripe rust, and has the effects of inhibiting spore germination of pathogenic bacteria, inducing systemic disease resistance of plants and promoting growth and development of wheat, and is environmentally friendly, residue-free, simple in preparation process, long in shelf life, and suitable for green prevention and control of wheat stripe rust, powdery mildew, scab and other plant diseases.

Description

Technical Field

[0001] This invention belongs to the field of agricultural plant protection, specifically relating to a water extract of Ganoderma lucidum fermentation liquid for the prevention and control of plant diseases and its application. Background Technology

[0002] Wheat is one of the most important food crops globally, and its yield and quality directly affect food security, agricultural economic development, and social stability. However, frequent outbreaks of wheat diseases and pests severely restrict the sustainable development of the wheat industry, among which wheat stripe rust is one of the most damaging fungal diseases. Wheat stripe rust is caused by *Striga styracifolium*, a wheat-specific fungal rust fungus. Puccinia striiformis f. sp. tritici This pathogen, caused by a fungus, is characterized by rapid spread, high mutation frequency, and a wide host range. It can spread over long distances via air currents and, under suitable temperature and humidity conditions, can quickly infect large areas of wheat fields. The pathogen exhibits highly variable pathogenicity, producing new races through sexual reproduction and asexual recombination, leading to a rapid "loss" of resistance in existing resistant wheat varieties. The breeding cycle for resistant varieties is over 8 years, far slower than the rate of pathogen mutation, creating a passive situation where "resistant varieties catch up with new races," making long-term effective control impossible. In the early stages of the disease, yellow to orange-yellow rust-like spore masses appear on wheat leaves. As the disease progresses, these spore masses gradually enlarge and rupture, releasing a large number of spores for further spread and infection. Infected wheat plants experience decreased photosynthetic efficiency, increased nutrient consumption, and stunted growth. In severe cases, it can lead to leaf withering, premature aging of the plant, and ultimately a significant drop in yield. Yields are typically reduced by 10%-30%, but in severe outbreaks, yields can drop by more than 70%, or even result in total crop failure. In addition, diseases can reduce the protein content, test weight and other quality indicators of wheat grains, affecting the commercial value and edible quality of wheat, causing huge economic losses to farmers.

[0003] Currently, the main methods for controlling wheat stripe rust include agricultural control, chemical control, disease-resistant breeding, and biological control. However, each method has limitations in practical application, making it difficult to achieve efficient and sustainable control of the disease.

[0004] Agricultural control measures mainly include rational crop rotation, removal of diseased plant debris from the field, optimization of planting density, and scientific water and fertilizer management. The core of these measures is to improve the field ecological environment, reduce the overwintering and transmission probability of pathogens, and enhance the wheat plant's own resistance. However, these measures suffer from slow effectiveness, limited control scope, and significant limitations imposed by geographical environment and planting patterns, making them ineffective in rapidly containing large-scale outbreaks of wheat stripe rust. For example, rational crop rotation requires corresponding adjustments to the crop planting structure, which is difficult to fully promote given the scarcity of land resources and the large-scale planting in major wheat-producing areas; removing diseased plant debris requires substantial labor costs and is unlikely to completely eliminate residual pathogens in the soil, resulting in limited control effectiveness.

[0005] Chemical control is currently the most common and direct method for controlling wheat stripe rust. By spraying chemical fungicides such as triadimefon, thiabendazole, tebuconazole, and fluopyram, the growth and reproduction of pathogens can be quickly inhibited, achieving good control effects in a short period of time. For example, the control efficacy of triadimefon spraying in the early stage of disease can reach more than 90%, and seed treatment with fungicides can reduce the incidence of disease in seedlings by 60% to 80%. However, the long-term and extensive use of chemical fungicides has brought about a series of serious environmental and ecological problems: First, pathogens are prone to developing drug resistance. Due to the selective pressure of chemical agents, the mutation rate of stripe rust fungus has accelerated, leading to a year-by-year decline in the control effect of commonly used agents, forcing farmers to increase the amount of pesticides used or change agents; Second, chemical agents remain in wheat grains, soil, and water bodies, which not only harm human health but also damage the soil microbial community structure, pollute the farmland ecological environment, and affect the sustainable development of agriculture; Third, the broad-spectrum killing effect of chemical agents can destroy beneficial microorganisms in the field, reduce the natural regulatory capacity of the farmland ecosystem, and may even lead to secondary outbreaks of other diseases and pests.

[0006] Disease resistance breeding involves screening and cultivating wheat varieties with disease-resistant genes to improve wheat's resistance to stripe rust at the genetic level, making it an economical and environmentally friendly control method. However, this technology has significant limitations: Firstly, the physiological races of wheat stripe rust are numerous and frequently mutate, with new virulent races constantly emerging. This can cause initially resistant varieties to lose their resistance after several years of planting. For example, Ug99 and its variants can break through several important wheat resistance genes (such as Sr31, Sr24, and Sr36), making 80%–90% of wheat varieties worldwide susceptible to it. Secondly, disease resistance breeding is a long and difficult process, requiring multiple generations of hybridization, screening, and identification, making it difficult to quickly respond to pathogen mutations and meet the demand for new disease-resistant varieties in production. Furthermore, some disease-resistant varieties may have poor agronomic traits (such as low yield and poor quality), hindering their widespread application in production.

[0007] Biological control, with its advantages of being environmentally friendly, less prone to developing resistance, and safe for humans and animals, has become a research hotspot in the field of agricultural disease control in recent years, and is considered an important direction for replacing chemical control and achieving green agricultural development. Currently, resources used for the biological control of wheat stripe rust mainly include antagonistic bacteria, antagonistic fungi, antagonistic viruses, and plant-derived active substances. Their mechanisms of action mainly include competitive elimination of pathogens, production of antimicrobial substances to inhibit pathogen growth, and activation of the plant's own defense system to induce disease resistance. However, firstly, only 10.5% of biopesticides are currently registered for the control of wheat stripe rust, resulting in a very narrow selection range; moreover, their efficacy is unstable and greatly affected by environmental factors such as temperature, humidity, and soil texture, making it difficult to achieve stable control effects under complex field conditions; secondly, some biopesticides have a narrow spectrum of action, effective only against specific physiological races of stripe rust fungi, making it difficult to address the diversity and variability of pathogens; thirdly, the production process of biopesticides is complex, and storage and transportation conditions are demanding, making it difficult to achieve large-scale industrial production and promotion; and fourthly, most of the reported biopesticide resources have low activity, requiring large-scale application to achieve the desired effect, further increasing application costs.

[0008] Based on the above situation, developing a product that has a wide range of raw material sources, is easy to prepare, is environmentally friendly, and can stably and efficiently prevent and control wheat stripe rust has become an urgent technical problem to be solved in current wheat agricultural production. Summary of the Invention

[0009] To address the aforementioned problems, this invention provides an aqueous extract of Ganoderma lucidum fermentation broth for the prevention and control of plant diseases, and its application. The aqueous extract of Ganoderma lucidum fermentation broth can be used as the sole effective active ingredient in the preparation of biocontrol agents for plant diseases. The resulting biocontrol agents have advantages such as high control efficiency, environmental friendliness, simple preparation process, and no adverse effects on wheat growth. They can achieve green and efficient control of common plant diseases such as wheat stripe rust, wheat powdery mildew, and Fusarium head blight. The aqueous extract of Ganoderma lucidum fermentation broth provided by this invention contains multiple active ingredients, which can inhibit bacteria at multiple targets and induce broad-spectrum disease resistance in plants, effectively solving the problems of narrow spectrum of action and difficulty in addressing the diversity and variation of stripe rust pathogens in traditional biocontrol agents.

[0010] This invention employs a segmented gradient liquid fermentation process to selectively enrich Ganoderma lucidum antibacterial metabolites, combined with a multi-stage hot water extraction process at 90℃~100℃ to efficiently dissolve polysaccharides and triterpenoids as core active ingredients. Segmented fermentation and multi-stage hot water extraction at 90℃~100℃ are indispensable steps in preparing highly active disease-preventing water extracts. The absence of either step will prevent the acquisition of the target product with highly efficient antibacterial, disease-inducing, and yield-promoting effects.

[0011] To achieve the above objectives, the specific technical solution of the present invention is as follows: The first aspect of this invention provides a water extract of Ganoderma lucidum fermentation broth for preventing and treating plant diseases. The water extract is obtained from Ganoderma lucidum through segmented liquid fermentation, extraction, and purification. The segmented liquid fermentation is divided into two stages: the culture temperature for the first to fourth days of liquid fermentation is 27℃ to 29℃, and the rotation speed is 130 r / min to 150 r / min; the culture temperature for the fifth to eighth days of liquid fermentation is 25℃ to 27℃, and the rotation speed is 110 r / min to 130 r / min. The extraction and purification involves water extraction at 90℃ to 100℃ 2 to 3 times, with each extraction lasting 0.5 h to 2 h.

[0012] Segmented culture is based on the growth and metabolic characteristics of Ganoderma lucidum, separating the rapid mycelial proliferation and antibacterial active substance synthesis stages. Following the defined segmented culture method, the yield of active substances and field control efficacy can be significantly improved.

[0013] Further, by weight-volume ratio, the culture medium for liquid fermentation comprises: 1% cornmeal, 1% wheat bran, 2% sucrose, 0.2% yeast extract, 0.3% peptone, 0.1% KH2PO4, 0.05% MgSO4·7H2O, with water to make up the difference.

[0014] A second aspect of the present invention provides a biocontrol agent, wherein the biocontrol agent uses the above-mentioned Ganoderma lucidum fermentation liquid water extract as the sole effective active ingredient.

[0015] Furthermore, the biocontrol agent includes the aqueous extract of the Ganoderma lucidum fermentation broth, as well as agriculturally acceptable adjuvants and / or fillers.

[0016] Furthermore, the water extract of the Ganoderma lucidum fermentation liquid is a solution, or it is freeze-dried into a powder after freeze-drying.

[0017] Furthermore, the additive is selected from one or more of surfactants, binders, humectants, thickeners, stabilizers, and antifreeze agents.

[0018] Further, by mass percentage, the biocontrol agent comprises: 10%–20% freeze-dried powder of Ganoderma lucidum fermentation broth extract, 0.5%–1.0% surfactant, 2%–5% binder or stabilizer, and the balance being filler; the surfactant is sorbitan fatty acid ester, the binder or stabilizer is polyethylene glycol, and the filler is talc. This biocontrol agent is a wettable powder, with a simple preparation process, suitable for large-scale production, and wide applicability. It can also be further processed into other formulations. The Ganoderma lucidum fermentation broth extract, as the core active ingredient, inhibits the growth of stripe rust fungus and induces disease resistance in wheat; sorbitan fatty acid ester, as a nonionic surfactant, enhances the wetting and spreading properties of the agent; polyethylene glycol, as a binder and stabilizer, prevents powder clumping and extends shelf life; and talc, as a filler, improves powder flowability and facilitates spraying.

[0019] Further, by mass percentage, the biocontrol agent comprises: 20%–25% Ganoderma lucidum fermentation broth aqueous extract, 0.5%–1% emulsifier, 0.3%–0.5% stabilizer, 5%–6% humectant, and the balance being water; the emulsifier is Tween 80, the stabilizer is xanthan gum, and the humectant is glycerin. This biocontrol agent is in liquid form, but can also be concentrated, dried into powder, and further processed into other formulations. In this biological control agent, the water extract of Ganoderma lucidum fermentation broth serves as the core active ingredient, which can inhibit the germination of wheat stripe rust spores and mycelial growth, inducing wheat to develop disease resistance. Tween 80, as an emulsifier, helps improve the dispersibility of the active ingredient, enhances the adhesion of the solution to the surface of wheat leaves, and improves the wetting and spreading properties of the agent. Xanthan gum, as a thickener, increases the viscosity of the formulation, prevents the active ingredient from settling and stratifying, and significantly improves the long-term storage stability of the product. At the same time, it enhances the adhesion of the solution to the surface of wheat leaves, reduces the drift and loss of the solution during spraying, improves the utilization rate of the agent, and prolongs the residence time of the active ingredient on the leaf surface. Glycerin, as a humectant, prolongs the effective period of the solution and reduces the loss of active ingredients due to water evaporation.

[0020] Further, by mass percentage, the biocontrol agent comprises: 20%–25% Ganoderma lucidum fermentation broth water extract, 0.5%–2% synergistic ingredient, 0.3%–1.5% emulsifier, 0.1%–1.0% thickener, 2%–10% humectant, 0.5%–3% stabilizer, and the balance being water; the synergistic ingredient comprises any one or more of chitosan, matrine, azadirachtin, allicin, organosilicon, azone, and potassium dihydrogen phosphate; and the emulsifier is Tween 60. The ingredients are: Tween-80, alkyl glycosides, sodium lignosulfonate, and soybean lecithin; the thickener is: sodium carboxymethyl cellulose, xanthan gum, CMC-Na, guar gum, bentonite, and silica; the humectant is: propylene glycol, glycerin, propylene glycol, sorbitol, and polyethylene glycol 400; and the stabilizer is: trehalose, vitamin C, disodium EDTA, citric acid, and phosphate buffer.

[0021] Furthermore, by mass percentage, the biocontrol agent comprises: 20%–25% water extract of Ganoderma lucidum fermentation broth, 1% synergistic ingredient, 0.8% emulsifier, 0.5% thickener, 6% humectant, 2% stabilizer, and the balance being water; the synergistic ingredient is chitosan, the emulsifier is Tween 60, the thickener is sodium carboxymethyl cellulose, the humectant is propylene glycol, and the stabilizer is trehalose. Through the synergistic effect of adjuvants, the limitations of single active ingredients are compensated for, balancing the cost of large-scale production with the effectiveness of field application.

[0022] The third aspect of this invention provides the application of the above-mentioned Ganoderma lucidum fermentation liquid water extract or biological control agent in the prevention and control of plant diseases, including wheat stripe rust, wheat powdery mildew and / or Fusarium head blight.

[0023] Further, the biocontrol agent is diluted with water 50 to 1000 times to obtain a working solution, which is then sprayed onto the plant leaves. The dilution can be adjusted according to the severity of the disease on the plant, but excessively high concentrations should not be used arbitrarily.

[0024] Furthermore, a spraying method is used to evenly spray the solution onto the front and back of wheat leaves, with a single application rate of 30 kg / mu to 45 kg / mu.

[0025] Furthermore, in preventing plant diseases: spray the working solution once every 10 to 15 days, for 2 to 3 consecutive applications; in the early stage of plant disease: spray the working solution once every 7 to 10 days, for 2 to 3 consecutive applications; if it rains, re-spray within 24 hours after the rain.

[0026] Furthermore, the prevention period for plant diseases is from the wheat jointing stage to the heading stage (10 to 15 days before the onset of stripe rust), and the initial stage of plant disease is when the diseased leaf rate is ≤5%. Precautions: Avoid spraying in high temperature (≥35℃), strong sunlight or windy weather; can be mixed with non-alkaline pesticides, but not with alkaline pesticides; store in a sealed container in a cool, dry place, shelf life 12 months.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention discloses a water extract of Ganoderma lucidum fermentation broth for the prevention and control of plant diseases and its application. The water extract of Ganoderma lucidum fermentation broth is prepared by Ganoderma lucidum through segmented liquid fermentation, residue removal, water extraction at 90℃~100℃, and purification. This invention uses the water extract of Ganoderma lucidum fermentation broth as the sole effective active ingredient, supplemented with agriculturally acceptable adjuvants and / or fillers, to prepare a biocontrol agent. The water extract of Ganoderma lucidum fermentation broth and the biocontrol agent have the advantages of high control efficiency, environmental friendliness, simple preparation process, and no adverse effects on the growth of crops such as wheat. It can achieve green and efficient control of common plant diseases such as wheat stripe rust, wheat powdery mildew, and Fusarium head blight. Details are as follows:

[0028] I. It effectively inhibits wheat stripe rust and has a significant control effect.

[0029] The aqueous extract of Ganoderma lucidum fermentation broth is rich in polysaccharides, triterpenoids, and other bioactive substances, exhibiting a direct and potent inhibitory effect on wheat stripe rust pathogen (Stripe rust fungus). This invention utilizes a synergistic process of segmented gradient fermentation and high-temperature multiple hot water extraction to maximize the enrichment of antibacterial active ingredients. On one hand, it significantly inhibits stripe rust spore germination, mycelial growth, and infection mat formation, blocking the disease progression at its source. Field trials have verified that the control effect on wheat stripe rust reaches over 80%, significantly superior to commercially available traditional biological control agents. On the other hand, it specifically targets the pathogenic mechanism of stripe rust fungus, reducing the pathogen's transmissibility and effectively controlling the spread of the disease. Especially under suitable temperature and humidity conditions for disease outbreaks, it maintains stable control efficacy, significantly reducing wheat yield loss caused by stripe rust (typically, wheat stripe rust can cause yield losses of over 75%, while this invention can control the yield loss rate to within 10%).

[0030] Second, induce wheat's own disease resistance to achieve long-term protection.

[0031] Unlike traditional control methods that simply kill pathogens, this invention achieves long-term disease resistance by activating wheat's own defense system. The active ingredients in the aqueous extract of Ganoderma lucidum fermentation broth can induce the activation of disease-resistance signaling pathways such as salicylic acid (SA) and jasmonic acid (JA) in wheat, significantly increasing the expression of pathogenesis-related protein (PR protein) genes. Simultaneously, it enhances the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) in wheat, reduces the content of lipid peroxidation products (MDA), and mitigates oxidative damage caused by pathogen infection. Wheat treated with this method exhibits disease resistance throughout its entire growth period and shows significant resistance to secondary infection of stripe rust, overcoming the drawback of traditional control agents requiring multiple applications.

[0032] Third, it promotes wheat growth and development, and improves yield and quality.

[0033] This invention not only prevents disease but also regulates growth. The active ingredients in the water extract of Ganoderma lucidum fermentation liquid can promote root development and plant growth, increase fresh weight, dry weight, and plant height, improve photosynthetic efficiency and chlorophyll content, and enhance nutrient absorption. Field trials show that wheat treated with this agent exhibits a significant increase in seed setting rate, a 1000-grain weight increase of 3%-27%, and a final yield increase of 4.5%-37.7% compared to the untreated group. Furthermore, since no chemical pesticides are required throughout the process, the impact of pesticide residues on wheat quality is avoided, improving the nutritional safety of the grains and meeting the requirements for green agricultural product production.

[0034] IV. Excellent environmental compatibility, green, safe and pollution-free.

[0035] This pesticide uses a water extract from the fermentation broth of Ganoderma lucidum, a natural edible and medicinal fungus, as its core ingredient. Its components are naturally biodegradable, leaving no residue in soil or water and causing no damage to the farmland ecosystem. Compared to chemical fungicides, it has no toxic effects on beneficial microorganisms in the soil (such as nitrogen-fixing bacteria and phosphate-solubilizing bacteria) and beneficial farmland organisms (such as earthworms and ladybugs), maintaining the stability of the soil microbial community structure and improving soil fertility. Simultaneously, it avoids the problem of pathogen resistance caused by long-term use of chemical pesticides, reducing the risks of pesticide residues to human health and the environment, aligning with the requirements of sustainable agricultural development and the "double reduction" policy (reducing pesticide use and pesticide residues).

[0036] V. Convenient for production and application, with outstanding cost-performance advantages.

[0037] The Ganoderma lucidum fermentation broth is prepared using liquid deep fermentation technology, resulting in a short production cycle (significantly shorter than that of artificially cultivated Ganoderma lucidum), high efficiency, and stable yield. Furthermore, the 90℃~100℃ hot water extraction process is simple, easy to implement, and cost-effective, making it suitable for large-scale industrial production and enabling bulk supply of the control agent. In terms of application, this control agent can be applied through conventional methods such as foliar spraying and seed coating. The operation is convenient, requires no special equipment, and is easy for farmers to master. Moreover, the dosage is low and the effect is long-lasting, reducing the frequency and amount of application and lowering farmers' planting costs. Compared with imported biological control agents and chemical fungicides, it has a significant cost-performance advantage and broad prospects for widespread application.

[0038] VI. It has a wide range of applications and strong resistance to adverse conditions.

[0039] The biocontrol agent of this invention exhibits good control and growth-promoting effects on wheat varieties with different genotypes, regardless of differences in disease resistance among wheat varieties. Furthermore, it maintains stable efficacy under various climatic conditions (such as arid, semi-humid, and humid regions) and soil types, and also has a certain inhibitory effect on other minor fungal diseases during wheat growth (such as wheat root rot), achieving "one agent for multiple preventions" and further enhancing its practical value in agricultural production. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 The preparation process of Ganoderma lucidum fermentation broth water extract and biocontrol agent.

[0042] Figure 2 To compare the field application effects of the control agent on wheat stripe rust. Control group 1: blank control sprayed with water; Control group 2: control sprayed with 25% triadimefon wettable powder (conventional dosage); Experimental group: sprayed with the biological control agent provided by this invention. Detailed Implementation

[0043] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Unless otherwise specified, the experimental methods described in the embodiments of the present invention are conventional methods, and the experiments are conducted under standardized experimental field or potted plant conditions. Unless otherwise specified, the materials and reagents used in the following embodiments are all conventional commercially available agricultural-grade raw materials.

[0044] In some embodiments of the present invention, the wheat varieties selected are Chuanmai 42, Ganmai 8, and Jimai 44, and the wheat stripe rust pathogen is the stripe rust physiological race "Tiaozhong 34" (CYR34), all of which are commercially available; Ganoderma lucidum ( Ganoderma lucidum The strain was purchased from the China General Microbiological Culture Collection Center, with accession number CGMCC 5.75.

[0045] Wheat stripe rust, caused by the fungus *Strombus styracifolius*, is a major global disease affecting wheat. It is characterized by rapid spread, wide range of damage, and severe losses. A large-scale outbreak can lead to yield reductions of 10%–30% in mild cases and total crop failure in severe cases. Currently, wheat stripe rust control primarily relies on chemical methods, with commonly used agents including triazole fungicides such as triadimefon and tebuconazole. However, long-term and excessive use of chemical pesticides can easily lead to drug resistance in pathogens, soil and water pollution, and threaten the quality and safety of agricultural products.

[0046] Biological control, with its advantages of being environmentally friendly, less prone to developing resistance, and safe for non-target organisms, has become an important development direction for the green control of agricultural diseases. Currently reported biocontrol agents for wheat stripe rust mainly include microbial preparations such as Trichoderma and Bacillus, whose mechanisms of action are mostly based on competing for nutrient space or inducing disease resistance in wheat. However, these preparations suffer from slow onset of action, short shelf life, and poor environmental adaptability. (Ganoderma lucidum...) Ganoderma lucidum As a traditional medicinal fungus, Ganoderma lucidum's fermentation products contain various bioactive components such as polysaccharides and triterpenoids, possessing antibacterial, anti-inflammatory, and immune-enhancing functions. Currently, Ganoderma lucidum extract is widely used in the preparation of hypoglycemic drugs and nutritional supplements.

[0047] Based on this, and addressing the technical bottlenecks of existing wheat stripe rust control methods, such as poor adaptability to pathogen variation, serious environmental pollution, unstable control effects, and a lack of green control materials, this invention provides a Ganoderma lucidum fermentation liquid water extract. This Ganoderma lucidum fermentation liquid water extract can be prepared into a highly efficient, stable, and environmentally friendly biological control agent for the green and sustainable control of plant diseases such as wheat stripe rust, taking into account both control effectiveness and agricultural ecological safety.

[0048] The Ganoderma lucidum fermentation broth aqueous extract and the biocontrol agent prepared therefrom provided by this invention have the following advantages: 1. Significant prevention and control effects: The polysaccharides and other active ingredients in the water extract of Ganoderma lucidum fermentation liquid can directly inhibit the germination of wheat stripe rust spores and mycelial growth, while inducing wheat to develop disease resistance and enhancing the plant's own immunity. The field control effect can reach more than 75%.

[0049] 2. Environmentally friendly and safe: The biocontrol agent uses natural fungal fermentation products as its core component, with no chemical pesticide residues. It does not pollute the ecological environment such as soil and water, and is safe for wheat, natural enemies and humans, meeting the needs of green agricultural development.

[0050] 3. Simple preparation process: Ganoderma lucidum liquid fermentation and water extraction processes are mature and can be scaled up through a four-stage fermentation tank group, resulting in low production costs; the biocontrol agent is a wettable powder, which is convenient to store and transport, and has a shelf life of more than 12 months.

[0051] 4. Wide range of applications: It is applicable to different wheat planting areas such as the Huang-Huai-Hai wheat region and the Northwest wheat region. It has a good control effect on stripe rust of different wheat varieties. It can be used in conjunction with measures such as planting disease-resistant varieties and reasonable crop rotation to improve the overall control effect.

[0052] Example 1: A water extract of Ganoderma lucidum fermentation liquid The preparation of Ganoderma lucidum fermentation broth aqueous extract includes the following steps: S1. Activation of Ganoderma lucidum strains: The Ganoderma lucidum strains were inoculated onto slant solid culture medium for activation culture. The activation conditions were: 25℃, cultured in the dark for 6 days to obtain activated strains.

[0053] The formula for the slant solid culture medium is: 20 w / v potato, 1 w / v acacia wood chips, 2 w / v glucose, 2 w / v agar, with the remainder being deionized water, and the pH being natural.

[0054] S2. Liquid fermentation scale-up culture: Inoculate the activated Ganoderma lucidum strain into 100mL of liquid culture medium, inoculating 10 pieces of 0.5cm in each bottle. 2 The inoculum blocks were subjected to primary shaking culture: on days 1-2, the culture was carried out at 26℃ and 110 r / min in the dark with shaking; on days 3-7, the culture was carried out at 28℃ and 140 r / min in the dark with shaking. The primary culture was then transferred to a 100L fermenter with liquid fermentation medium at an inoculation rate of 8 v / v% for secondary scale-up culture. The entire fermentation process was strictly carried out in stages: on days 1-4, the culture temperature was 28℃ and the shaking speed was 140 r / min; on days 5-8, the culture temperature was 26℃ and the shaking speed was 120 r / min in the dark with shaking, to obtain the Ganoderma lucidum fermentation broth.

[0055] Liquid microbial culture medium formula: 20 w / v potato, 1 w / v albizia wood chips, 2 w / v glucose, with the remainder being deionized water, pH natural.

[0056] Liquid fermentation medium formula: cornmeal 1 w / v%, wheat bran 1 w / v%, sucrose 2 w / v%, yeast extract 0.2 w / v%, peptone 0.3 w / v%, KH2PO4 0.1 w / v%, MgSO4·7H2O 0.05 w / v, balance deionized water, pH natural.

[0057] S3. Preparation of aqueous extract of fermentation broth: The fermented Ganoderma lucidum broth was filtered through a plate and frame filter to remove mycelial residue and collect the filtrate. The collected filtrate was extracted twice with hot water at 95℃ for 1 hour each time. The extracts were combined to 30L and concentrated to 3L using a rotary evaporator. After freeze-drying, the extract was pulverized and passed through a 200-mesh sieve to obtain 0.8kg of dry powder Ganoderma lucidum fermentation broth aqueous extract. The polysaccharide content was tested to be 18.2w / w.

[0058] Example 2: A water extract of Ganoderma lucidum fermentation liquid The preparation of Ganoderma lucidum fermentation broth aqueous extract includes the following steps: S1. Preparation of Ganoderma lucidum seed liquid: Ganoderma lucidum strain was inoculated into PDA slant medium and cultured at 28℃ for 7 days to activate the strain; 3 pieces of activated mycelial blocks with a diameter of 5mm were picked and inoculated into a 500mL Erlenmeyer flask containing 100mL of fermentation medium and cultured at 28℃ and 180r / min for 3 days to obtain Ganoderma lucidum seed liquid. Fermentation medium: glucose 20g / L, peptone 5g / L, yeast extract 3g / L, KH2PO4 1g / L, MgSO4·7H2O 0.5g / L, distilled water 1L, pH adjusted to 6.5.

[0059] S2. Preparation of Ganoderma lucidum fermentation broth: Inoculate Ganoderma lucidum seed liquid into the fermentation tank (60% liquid volume) at an inoculation rate of 5% (v / v) and carry out segmented fermentation culture: Day 1 to Day 4 of fermentation, culture temperature 27℃, rotation speed 130r / min; Day 5 to Day 8 of fermentation, culture temperature 25℃, rotation speed 110r / min. After fermentation, filter with 4 layers of gauze to remove mycelium and obtain Ganoderma lucidum fermentation broth.

[0060] S3. Preparation of Ganoderma lucidum fermentation broth aqueous extract: The fermentation broth was first extracted three times with hot water at 90℃, 0.5h each time, and the extract was collected after filtration to remove residue. The Ganoderma lucidum fermentation broth was placed in a rotary evaporator and concentrated under reduced pressure at 55℃ to 1 / 5 of the original volume to obtain a concentrated solution. Three times the volume of deionized water was added to the concentrated solution, and after stirring evenly, it was refrigerated at 4℃ and allowed to stand for 12h. Then, it was centrifuged at 8000r / min for 15min, and the supernatant was collected. The supernatant was concentrated again under reduced pressure to a solid content of 20% (mass fraction) to obtain the Ganoderma lucidum fermentation broth aqueous extract.

[0061] The polysaccharide content of the water extract of Ganoderma lucidum fermentation broth was 2.7 w / v, which is equivalent to 13.5 w / w in dry solids, as determined by the phenol-sulfuric acid method.

[0062] Example 3: A water extract of Ganoderma lucidum fermentation liquid The preparation of Ganoderma lucidum fermentation broth aqueous extract includes the following steps: S1. Preparation of Ganoderma lucidum seed liquid: Ganoderma lucidum strain was inoculated into PDA slant medium and cultured at 28℃ for 7 days to activate the strain; 3 pieces of activated mycelial blocks with a diameter of 5mm were picked and inoculated into 500mL Erlenmeyer flasks containing 100mL fermentation medium and cultured at 28℃ and 180r / min for 3 days to obtain Ganoderma lucidum seed liquid.

[0063] Fermentation medium: glucose 20g / L, peptone 5g / L, yeast extract 3g / L, KH2PO4 1g / L, MgSO4·7H2O 0.5g / L, distilled water 1L, pH adjusted to 6.5.

[0064] S2. Preparation of Ganoderma lucidum fermentation broth: Ganoderma lucidum seed liquid was inoculated into a fermenter (65% liquid volume) at an inoculation rate of 8% (v / v) and subjected to segmented fermentation culture: day 1 to day 4 of fermentation, culture temperature 29℃, rotation speed 150 r / min; day 5 to day 8 of fermentation, culture temperature 27℃, rotation speed 130 r / min; 24 hours before the end of fermentation, 0.5 g / L of methyl jasmonate was added to the fermenter to specifically induce Ganoderma lucidum to synthesize more antibacterial triterpenes, and then the mycelium was removed by filtration to obtain Ganoderma lucidum fermentation broth.

[0065] S3. Preparation of Ganoderma lucidum fermentation broth aqueous extract: The fermentation broth was first extracted twice with hot water at 100℃ for 2 hours each time. The extract was collected after filtration to remove residue. The extract was concentrated under reduced pressure at 60℃ to 1 / 4 of its original volume to obtain a concentrated solution. Four times the volume of deionized water was added to the concentrated solution, and after stirring evenly, it was refrigerated at 4℃ for 16 hours and centrifuged at 10000r / min for 20 minutes. The supernatant was collected. The supernatant was filtered through an ultrafiltration membrane (molecular weight cutoff of 1000Da), and the permeate was collected and concentrated under reduced pressure to a solid content of 25% (mass fraction) to obtain the Ganoderma lucidum fermentation broth aqueous extract.

[0066] The polysaccharide content was determined to be 2.2% (mass fraction, on a liquid basis) by the phenol-sulfuric acid method, which translates to 8.8% polysaccharide content in dry solids.

[0067] The content is lower than that in Example 2, mainly because this example uses a 1000Da ultrafiltration membrane, which retains some of the large-molecule polysaccharides; however, methyl jasmonate induces a 42% or higher increase in the content of triterpenoid compounds compared to Example 2, resulting in stronger overall antibacterial activity and making it more suitable for preparing highly active formulations.

[0068] Example 4: A biological control agent (wettable powder) and its application in the field control of plant diseases. 1. Preparation of biological control agents The preparation process flow is as follows: Figure 1 The components were weighed according to the following mass percentages: 15 w / w of water extract of Ganoderma lucidum fermentation liquid prepared in freeze-dried powder form in Example 1, 0.8 w / w of sorbitol fatty acid ester, 3 w / w of polyethylene glycol 1500, and 81.2 w / w of talc.

[0069] The components were mixed in a mixer for 15 minutes, then pulverized in an ultra-fine pulverizer. After pulverization, the mixture was passed through a 250-mesh sieve and mixed again for 10 minutes to obtain 1 kg of the finished biological control agent. The finished product was tested and found to have good flowability, a wetting time of ≤60s, and a suspension rate of ≥85%.

[0070] In wettable powders: Ganoderma lucidum fermentation liquid water extract serves as the core active ingredient, which can inhibit the growth of stripe rust fungus and induce disease resistance in wheat; dehydrated sorbitan fatty acid esters serve as nonionic surfactants, which enhance the wetting and spreading properties of the agent; polyethylene glycol serves as a binder and stabilizer, which prevents the powder from clumping and extends the shelf life; talc serves as a filler, which improves the flowability of the powder and facilitates spraying.

[0071] 2. Field efficacy trials Field control trials were conducted in wheat experimental fields in the Huang-Huai-Hai wheat region. The tested wheat variety was "Ganmai 8". The experiment was set up with 3 treatment groups, each with 3 replicates, and the plot area was 20m². 2 The row spacing was 25cm, and the planting density was 250,000 plants per mu (approximately 0.16 acres). The first application of pesticide was performed at the wheat jointing stage, with other field management conditions remaining consistent. The treatments are as follows:

[0072] ① Experimental group: The biocontrol agent prepared in this embodiment was diluted 800 times with water to obtain the working solution, and then 35 kg of the working solution was sprayed per acre; ② Control group 1: Sprayed with the same volume of water as the experimental group; ③ Control group 2: Spray 25% triadimefon wettable powder (diluted 1000 times with water), using 35 kg of the solution per mu.

[0073] A second application was performed 7 days after the initial application, using a backpack sprayer for foliar spraying to ensure even coverage on both sides of the wheat leaves, with a focus on the middle and lower leaves. If rain occurred within 6 hours of the initial application, a re-application was necessary. Disease index was assessed 14 days after application, and the control effect was calculated. The results are shown in Tables 1 and 2. Figure 2 .

[0074] Table 1 Statistical Results of Prevention and Control Effects Note: "-" in the table indicates that the corresponding indicator is not included in the statistics.

[0075] Table 2 Statistical results of major agronomic traits at wheat maturity Depend on Figure 2 As shown in Tables 1 and 2, the biological control agent of this invention has a control effect of 87.2% on wheat stripe rust, which is significantly better than that of conventional chemical agent triadimefon. Moreover, the wheat plants showed no phytotoxicity symptoms, and the main agronomic traits such as plant height at maturity, number of effective spikes, thousand-grain weight, and number of grains per spike were significantly better than those of the water control group and the chemical agent control group. This indicates that the biological control agent of this invention can not only effectively control the disease, but also promote wheat growth and increase yield potential.

[0076] Depend on Figure 2 It can be seen that: the diseased leaf rate of wheat in control group 1 reached 88.6%, and the wheat leaves were covered with yellow stripe rust spore masses, indicating a high disease index; the diseased leaf rate of wheat in control group 2 was 23.5%, and the wheat leaves had fewer lesions; the diseased leaf rate of wheat in the experimental group was 12.8%, and the wheat leaves had only a few scattered lesions. The control effect was better than that of the chemical control, and the wheat plants grew vigorously without any phytotoxicity symptoms, verifying the excellent control effect of the biological control agent provided by this invention.

[0077] Example 5: Preparation and application of a basic liquid biological control agent 1. Preparation of basic liquid biocontrol agent: 20 w / w% of the water extract of Ganoderma lucidum fermentation broth prepared in Example 2, 0.5 w / w% of Tween 80, 0.3 w / w% of xanthan gum, and 5 w / w% of glycerol were mixed by mass fraction. The remainder was made up with deionized water. After stirring evenly, the mixture was filtered through a 0.22 μm filter membrane for sterilization to obtain a basic liquid biocontrol agent.

[0078] In the basic liquid biological control agent: Ganoderma lucidum fermentation broth water extract serves as the core active ingredient, which can inhibit the germination of wheat stripe rust spores and mycelial growth, inducing wheat to develop disease resistance; Tween 80, as an emulsifier, helps improve the dispersibility of the active ingredient, enhances the adhesion of the solution to the surface of wheat leaves, and improves the wettability and spreading properties of the agent; Xanthan gum, as a thickener, increases the viscosity of the formulation, prevents the active ingredient from settling and stratifying, and significantly improves the long-term storage stability of the product; at the same time, it enhances the adhesion of the solution to the surface of wheat leaves, reduces the drift and loss of the solution during spraying, improves the utilization rate of the agent, and prolongs the residence time of the active ingredient on the leaf surface; Glycerin, as a humectant, prolongs the effective period of the solution and reduces the loss of active ingredients due to water evaporation.

[0079] 2. Verification of effects A pot experiment was conducted, selecting wheat seedlings (Chuanmai 42) at the 3-leaf stage with uniform growth, dividing them into 3 groups of 30 seedlings each, with 3 replicates: ① Experimental group: The basic liquid biocontrol agent prepared in this embodiment was diluted 800 times with water to obtain the working solution. The spraying rate of the working solution was 60 mL / m². 2 Spray evenly on both sides of wheat leaves; spray the working solution once every 12 days, for a total of 2 applications.

[0080] ② Positive control group: Spray with 20% triadimefon emulsifiable concentrate (a conventional chemical control agent), diluted 1000 times and applied at the same dosage.

[0081] ③ Blank control group: sprayed with an equal amount of deionized water.

[0082] 24 hours after two consecutive applications, a suspension of wheat stripe rust fungus urediniospores (concentration 1×10⁻⁶) was sprayed into the solution. 5 Wheat leaves were inoculated with samples per mL and then placed in an artificial climate chamber at 20°C, 90% relative humidity, and 12h / d light. The incidence of wheat stripe rust was observed regularly during the incubation period.

[0083] Twenty-one days after pathogen inoculation, the disease index of wheat in each group was investigated in accordance with the "Standard for Monitoring and Forecasting of Wheat Stripe Rust". The control effect of biological control agents on wheat stripe rust was calculated. At the same time, the agronomic traits of wheat (plant height and fresh weight) were measured. The results are shown in Table 2 below.

[0084] Table 2. Statistics on the control effects of basic liquid biological control agents Note: "-" in the table indicates that the corresponding indicator is not included in the statistics.

[0085] Table 2 shows that the basic liquid biological control agent prepared in this embodiment achieved a control effect of 72.3% on wheat stripe rust, which is slightly lower than that of conventional chemical agents, but significantly better than that of the blank control group. At the same time, the plant height and fresh weight of wheat in the experimental group were higher than those in the positive control group and the blank control group, indicating that this basic liquid biological control agent can not only control wheat stripe rust, but also promote wheat growth.

[0086] Example 6: Preparation and application of an enhanced liquid biological control agent 1. Preparation of enhanced liquid biocontrol agent: By mass fraction, 25% of the Ganoderma lucidum fermentation broth water extract prepared in Example 3, 1% chitosan (molecular weight 5000 Da), 0.8% Tween 60, 0.5% sodium carboxymethyl cellulose, 6% propylene glycol, and 2% trehalose were mixed, and the remaining part was made up to 100% with deionized water. After stirring evenly, the mixture was filtered through a 0.22 μm filter membrane for sterilization to obtain an enhanced liquid biocontrol agent.

[0087] This formula employs a "core active ingredient enhancement + synergistic effect of multiple adjuvants" approach. Specifically, Ganoderma lucidum fermentation extract serves as the core active ingredient, effectively inhibiting bacteria and inducing systemic disease resistance in wheat; chitosan, as a bio-derived synergist and film-forming agent, synergistically inhibits bacteria, prolongs the duration of action, and induces disease resistance; Tween 60, as a non-ionic emulsifier, improves the dispersibility of the active ingredient and the wetting and spreading properties of the solution; sodium carboxymethyl cellulose, as a thickener, improves storage stability, enhances the adhesion of the solution, and reduces drift; propylene glycol, as a humectant and antifreeze agent, prolongs the action time and improves low-temperature storage stability; and trehalose, as a bio-stabilizer, protects the structure of active molecules and extends the shelf life to over 18 months.

[0088] 2. Verification of effects A field plot experiment was conducted. The experimental plots had uniform soil fertility, and the previous crop was maize. The wheat (Ganmai 8) was planted at a density of 2.25 million plants / hectare. The experimental plots were divided into 4 groups, with each plot measuring 20m². 2 3 repetitions, randomized block arrangement:

[0089] ① Experimental group: The basic liquid biocontrol agent prepared in this embodiment was diluted 800 times with water to obtain the working solution. The spraying rate of the working solution was 60 mL / m². 2 Spray once each during the wheat jointing stage and the heading stage, with an interval of 10 days; ② Positive control group: Spray with 20% triadimefon emulsifiable concentrate (diluted 1000 times), using the same spraying amount and spraying time; ③Basic control group: The basic liquid biological control agent prepared in Example 5 was sprayed, and the spraying amount and spraying time were the same as those of the experimental group; ④ Blank control group: sprayed with an equal amount of deionized water.

[0090] During the wheat growing season, the wheat was naturally susceptible to disease (there were wheat stripe rust-infected fields around the experimental field to ensure a sufficient source of inoculum), and the disease situation was observed regularly.

[0091] During the wheat maturity period, the disease index and control effect of each plot were investigated. At the same time, the effective number of spikes, number of grains per spike, thousand-grain weight and yield of wheat were measured. The results are shown in Table 3 below.

[0092] Table 3. Statistical analysis of the control effects of enhanced liquid biological control agents. Note: "-" in the table indicates that the corresponding indicator is not included in the statistics.

[0093] The results showed that the enhanced liquid biological control agent prepared in this embodiment achieved a control effect of 84.7% against wheat stripe rust, comparable to conventional chemical agents (85.8%). Regarding wheat yield increase, the yield of the experimental group (9258 kg / ha) was significantly higher than that of the positive control group (8862 kg / ha), and compared with the yield of the blank control group (6723 kg / ha), the yield increase rate after applying the basic liquid biological control agent (8535 kg / ha) reached 37.7%. Furthermore, no phytotoxicity symptoms were observed in the experimental group wheat during the experiment, indicating that this enhanced liquid biological control agent has high safety and is suitable for large-scale field application.

[0094] Example 7: Preparation of a biological control agent 1. The preparation process of the biocontrol agent in this embodiment is simple and controllable, and suitable for industrial production. The specific steps are as follows: Based on the total mass of the biocontrol agent, 0.5 w / v% Tween 80 and 5 w / v% glycerol were added sequentially to deionized water and stirred until completely dissolved (stirring speed 400 r / min, time 12 min); then 10 w / v% of the Ganoderma lucidum fermentation broth water extract from Example 3 was slowly added and stirred for another 30 min to obtain a uniformly dispersed biocontrol agent without stratification or precipitation.

[0095] Finished product inspection: The compounded biological control agent is tested for pH value (standard: 6.0-7.5), stability (no stratification after standing for 30 days), and active ingredient content. After passing the test, it is packaged and stored.

[0096] 2. Indoor toxicity test of biological control agents Experimental materials: wheat stripe rust fungus spores (collected from diseased wheat in the field), the biological control agent used in this example, and the control agent (25% triadimefon wettable powder, a mainstream commercially available chemical agent); Experimental method: The spore germination inhibition method was adopted. The biocontrol agent of this embodiment was diluted 50 times, 100 times, and 200 times, and the control agent was diluted 500 times (500 times is the recommended concentration). The blank control group (deionized water) was also included. Each group was repeated 3 times. The drug solution of each treatment group was mixed with the suspension of pathogenic spores and placed in a constant temperature incubator at 20℃ for 24 hours. The spore germination rate was counted and the inhibition rate was calculated. The experimental results are shown in Table 4.

[0097] Table 4. Statistics on the inhibition rate of biological control agents on the germination of wheat stripe rust fungus spores. As shown in Table 4, the biocontrol agent, when diluted 100 times, can inhibit the germination of wheat stripe rust spores by 83.8%; when diluted 50 times, the biocontrol agent can inhibit the germination of wheat stripe rust spores by 91.3%, and the control effect is better than that of mainstream commercially available chemical agents.

[0098] 3. Field plot trials of biological control agents Winter wheat variety "Jimai 44" was planted in wheat planting bases in areas with a high incidence of stripe rust over the years, with a planting area of ​​1 mu / plot. The following groups were set up: a 50-fold dilution group and a 100-fold dilution group of the biocontrol agent used in this embodiment; a 500-fold dilution group of the control agent (25% triadimefon) (500-fold dilution is the recommended concentration); and a blank control group (deionized water). Each group was replicated three times. Spraying was carried out by misting, evenly spraying the upper and lower surfaces of wheat leaves. During the prevention period, spray once every 12 days for two consecutive applications; during the treatment period, spray once every 8 days for three consecutive applications. The single application rate per mu was 35 kg of diluted solution.

[0099] The experimental results are shown in Table 5: Table 5. Statistical analysis of the control efficacy of biological control agents against wheat stripe rust fungus. As shown in Table 5, the biological control agent can achieve a control effect of over 81% on wheat stripe rust under field conditions, and can significantly increase wheat yield. At the same time, it has no phytotoxicity to wheat growth (no yellowing or wilting of leaves, and no difference in plant height and tiller number compared with normal plants), and its environmental safety is better than that of the chemical control agent.

[0100] The Ganoderma lucidum fermentation broth aqueous extract and the biocontrol agent prepared therefrom provided by this invention have the following advantages: 1. To address the technical challenges of unstable control effects, slow onset of action, and significant environmental impact of existing biological control agents for wheat stripe rust, a biological control agent with significant control effects, strong stability, and broad environmental adaptability will be developed by utilizing the specific antibacterial active ingredients contained in Ganoderma lucidum fermentation broth. This will enable efficient and precise control of wheat stripe rust, reducing the incidence and severity of the disease.

[0101] 2. To fill the technological gap in the application of Ganoderma lucidum fermentation broth water extract in the prevention and control of wheat stripe rust, clarify the optimal extraction process, active ingredient enrichment method, and application concentration, timing and method of Ganoderma lucidum fermentation broth water extract, improve the utilization rate of active ingredients, and solve the problem of unclear agricultural application parameters of existing Ganoderma lucidum extracts.

[0102] 3. Overcome the drawbacks of chemical pesticides, such as environmental pollution and resistance, and the high cost of biological pesticides, and provide an environmentally friendly, low-toxicity, residue-free, and low-cost biological control agent to reduce the use of chemical pesticides, protect the ecological balance of farmland, ensure the quality and safety of wheat and human health, and promote the sustainable development of green agriculture.

[0103] 4. Achieve synergistic effects of prevention and control and increased yield. Through the antibacterial effect of Ganoderma lucidum fermentation liquid water extract and its regulatory effect on the physiological and biochemical processes of wheat plants, enhance the disease resistance of wheat itself, improve the soil micro-ecological environment, promote wheat growth and development, and increase wheat yield and quality, thus solving the problem of poor synergy between disease resistance and yield in existing disease-resistant varieties.

[0104] 5. Provide a simple, easy-to-implement, and scalable biological control application scheme for wheat stripe rust, reduce the difficulty of promoting control technologies, provide new technical support for the comprehensive control of wheat stripe rust, alleviate the contradiction between the lagging renewal of disease-resistant varieties and the rapid mutation of stripe rust fungus, and ensure the safe production of wheat industry.

[0105] It should be noted that when numerical ranges are involved in this invention, it should be understood that both endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as in the embodiments, preferred embodiments are described here to avoid redundancy. Although preferred embodiments of the invention have been described, those skilled in the art, once they understand the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this invention.

[0106] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A water extract of Ganoderma lucidum fermentation liquid for preventing and treating plant diseases, characterized in that, The Ganoderma lucidum fermentation broth water extract is obtained from Ganoderma lucidum through segmented liquid fermentation, extraction and purification; the segmented liquid fermentation is divided into two stages: the culture temperature for the first to fourth days of liquid fermentation is 27℃~29℃ and the rotation speed is 130r / min~150r / min; the culture temperature for the fifth to eighth days of liquid fermentation is 25℃~27℃ and the rotation speed is 110r / min~130r / min; the extraction and purification is carried out by water extraction at 90℃~100℃ 2 to 3 times, each extraction for 0.5h~2h.

2. A biological control agent, characterized in that, The biocontrol agent includes the Ganoderma lucidum fermentation broth aqueous extract as described in claim 1, as well as agriculturally acceptable adjuvants and / or fillers; the Ganoderma lucidum fermentation broth aqueous extract is a solution, or is freeze-dried into a freeze-dried powder after freeze-drying treatment; the adjuvants are selected from one or more of surfactants, binders, humectants, thickeners, stabilizers and antifreeze agents.

3. The biological control agent according to claim 2, characterized in that, The biocontrol agent comprises, by weight percentage: 10%~20% freeze-dried powder of Ganoderma lucidum fermentation broth extract, 0.5%~1.0% surfactant, 2%~5% binder or stabilizer, and the balance being filler; the surfactant is sorbitan fatty acid ester; the binder or stabilizer is polyethylene glycol; and the filler is talc.

4. The biological control agent according to claim 2, characterized in that, The biocontrol agent comprises, by weight percentage: 20%~25% Ganoderma lucidum fermentation broth water extract, 0.5%~1% emulsifier, 0.3%~0.5% stabilizer, 5%~6% humectant, and the balance being water; the emulsifier is Tween 80; the stabilizer is xanthan gum; and the humectant is glycerin.

5. The biological control agent according to claim 2, characterized in that, The biocontrol agent, by weight percentage, comprises: 20%–25% water extract of Ganoderma lucidum fermentation broth, 0.5%–2% synergistic ingredient, 0.3%–1.5% emulsifier, 0.1%–1.0% thickener, 2%–10% humectant, 0.5%–3% stabilizer, and the balance being water; the synergistic ingredient comprises any one or more of chitosan, matrine, azadirachtin, allicin, organosilicon, azone, and potassium dihydrogen phosphate; the emulsifier is Tween 60, Tween 40, Tween 50, Tween 6 ... The ingredients include: W-80, alkyl glycosides, sodium lignosulfonate, and soybean lecithin; the thickener is any one or more of sodium carboxymethyl cellulose, xanthan gum, CMC-Na, guar gum, bentonite, and silica; the humectant is any one or more of propylene glycol, glycerin, propylene glycol, sorbitol, and polyethylene glycol 400; and the stabilizer is any one or more of trehalose, vitamin C, disodium EDTA, citric acid, and phosphate buffer.

6. The application of the aqueous extract of Ganoderma lucidum fermentation liquid according to claim 1 or the biocontrol agent according to any one of claims 2 to 5 in the control of plant diseases, characterized in that, The plant diseases mentioned include wheat stripe rust, wheat powdery mildew, and / or Fusarium head blight.

7. The application according to claim 6, characterized in that, The biological control agent is diluted with water 50 to 1000 times to obtain a working solution, which is then sprayed onto the plant leaves.

8. The application according to claim 7, characterized in that, The dosage of the working solution used in a single application is 30 kg / mu to 45 kg / mu.

9. The application according to claim 8, characterized in that, When preventing plant diseases: spray the above-mentioned working solution once every 10 to 15 days, and apply it 2 to 3 times consecutively; when the disease is in its early stage: spray the above-mentioned working solution once every 7 to 10 days, and apply it 2 to 3 times consecutively.

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